Warsaw, Sep 10 (Xinhua) The North Atlantic Treaty Organisation (NATO) needs to send more troops to Afghanistan to reinforce its military presence there, NATO's Military Committee Chairman Ray Henault said here.

Henault made the appeal Saturday at a meeting of top military officers of NATO's 26 members in the Polish capital, where the participants would discuss NATO's operations in Afghanistan and elsewhere at the two-day meeting.

"Afghanistan is the most complex mission NATO has ever undertaken," he said.

Taliban has put up a staunch resistance which is far more fierce than previously expected, thus it is necessary to send extra troops to fight Taliban insurgents in southern Afghanistan, he said.

Henault said he would appeal formally to the military alliance's council Monday for some additional 2,000-2,500 soldiers.

NATO has 21,000 troops in Afghanistan. NATO forces have launched large-scale operations against Taliban insurgents over the past few days.

The alliance moved into southern Afghanistan and took over command from the US in July.